Mail The mail function allows you to send mail SMTP string DNS name or IP address of the SMTP server PHP under Windows should use for mail sent with the mail function. sendmail_from string Which "From:" mail address should be used in mail sent from PHP under Windows. sendmail_path string Where the sendmail program can be found, usually /usr/sbin/sendmail or /usr/lib/sendmail configure does an honest attempt of locating this one for you and set a default, but if it fails, you can set it here. Systems not using sendmail should set this directive to the sendmail wrapper/replacement their mail system offers, if any. For example, Qmail users can normally set it to /var/qmail/bin/sendmail. &reference.mail.functions;